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Cisco 877 Max VLAN and QoS Bugs??

Hi All,

Sorry for the double post but I need to get this issue resolved ASAP.

I am currently configuring a Cisco 877 router and I believe that I have run into a software bug with the 877.

The unit shipped with IOS 124-4.T2, I was able to configure 4 additional VLANs to the default VLAN through the VLAN database as expected and everything was working fine until I tried to apply my QoS service-policy to the Dialer Interface. Unexpectedly the router suffered a software forced reload and dumped it's output to flash. When the unit came up again I tried to apply the service-policy, same story the unit crashed.

I then downloaded 124-6.T1 and proceeded to recreate my VLANS, the VLAN.dat file copied successfully back to flash but the VLANS were not visible? (yet another bug??) When trying to recreate my VLANS as I added the fifth VLAN the following error occured.

*****UKBURL877-001(vlan)#vlan 5 name Guest*****

*****Vlan can not be added. Maximum number of 4 vlan(s) in the database.*****

I have now just upgraded to 124-6.T2 (release date 18/05) and when adding in the fifth VLAN the same error as above occurs.

I didn't even bother trying to add the service-policy after the IOS upgrades as my project requires 5 VLANs in total.

Anbody else running into the same bug?????

When my Smartnet comes through i'm going to open up a TAC on this but until then I was hoping that somebody out there might have an answer. ; )




Re: Cisco 877 Max VLAN and QoS Bugs??

Dear Steve,

I found it for you

Q)How many 802.1q VLANs can be configured on the inbuilt 4 port switch (Fastethernet 0-3) ?

A. Maximum of 4 VLANs are supported on Cisco 870 series with the plus feature set(Advanced IP services/Advanced Enterprise Services). Cisco 850 series does not support 802.1q VLANs.

For more info refare to

Please rate helpful posts.

Best Regards,

Mounir Mohamed

Community Member

Re: Cisco 877 Max VLAN and QoS Bugs??


With respect, I am fully aware that the 877 supports 4 802.1q VLANS in addition to the default VLAN, VLAN 1. When upgrading to the most current IOS (124-6.T2)the 877 now only supports 4 VLANS including the default VLAN.

Plus i'm guessing my QoS service-policy when applied to the dialer interface is still going to crash the router.

Community Member

Re: Cisco 877 Max VLAN and QoS Bugs??


Just hit the same VLAN bug on an 878 with 12.4(6)T3. Same problem - only four VLANs *including* the default VLAN. Did you get a TAC up on this because if not I have one going in tomorrow?



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